Formaldehyde condensation products of mercaptans and process for making same



Patented May 17 1949 PATENT OF armsss ,FORMALDEHYDE I: CONDENSAIIIBN PROD- ;UQTS'Q'OFI'MERCAPTANS AND 'BROGESS "FOR; "MKKING'ifSAME 'irMai'ion :W. Harmanpliitro, W. Va., assignor to "EMons antoiGhemicjal Company, St. Louis, Mo.,

a corporatiomof llelaware NDrawing; rknplicationfictdbet-i), 1945,

" eam No. 6214387 The 'present :inventton relates :tomeimnheminal :compounds zandxtotthe:processmf theirtspizeparation.

,Thercompoundscof the rpresentcmrentionmomrpri'se ireazctionaapmducts ao'f "sorganicmmemaptans with formaldehyd-eazand t ammonia. awhile :mrer- 1Similarly;trisimercaptomethyl)caminesgieeacompounds or the ,z generalstnucturew =QR+SGHzhN .1where --ZR-:is an1organic-'radical,.;'areknown. @The new compounds 1 are reaction; products, cot imero-aptans, dormaldehyde andsammonia *containln a-more than enezmolecular proportionrifriormaldehyde and :iess :lthanv one; .moleculare-iproportiontof ammonia combinedswtth each xmoleculary proportiomoflthamercaptan.

In accordance Withlthe present invention it has been found that organic mercaptans condense in aqueous medium with ammonia and formaldehyde in substantial excess of the ,molecular proportion of the mercap-tan to .producewvaluable products. The reaction is conducted with the free mercaptans although it is preferable to add a small amount of alkalitsufiicient to render the charge slightly alkaline in thec-aabserroewofligthe ammonia.

' :flhezreantions rarecbest effected :in aqueousme- Ilium i-sincemrganic :solvents .seem' auto favor. the 'ltormationz-pf Ibyaproducts cwhichrdo not contain theihighrproportron voflzfonnaldehyde :HOHStitl-IEHJJ characteristicrof .tthe mew compounds. The :fol-

lowing:examplezilius-tratesithe.zpreparationaaof one -0fz1thez-snewmompounds butxis rnot limitative of zthei'inventton.

xam

Into-a container df suitable capacity fitted'with can efi'lcient stirrer and reflux condenser there ::was charged'wfi parts by weight (substantially 1.2' molecular proportions) of finely powdered mercaptobenzothiazole, 164 parts'byweight (substantiallyZ molecular proportions) of 37%.formfaildehs'gde and 1000 parts by weight of Water. The

.'; 'mixture .stirred until a "thin .slurry was formed, 'then ahoutj Lpart by weight ofv soda ash "addetl or enougnto render the Charge slightly alkaline;iollowed'*byf28"parts by weight (sub- :Stantially' 'OAB j molecular 'proportion) of ammonium hydroxide sp. 'g.' 0i90 dilutedwith 1001parts noyweight o'f water. 1 The addition of the ammo- *nia brought about a slight exothermic reaction. The 'mass was stirredand s'lowly 'heatediupyto 90 "'C.' overca period o'fabout three'fhours. Heating and stin'ing-was then continued at 90-95 10175 $01-20 hours and "the massfiltered hot. Ex- 'cllent yieldswere obtained overthis entire'range of heating periodsand only slight improvements were noticeableupomheating "longer than five hours. The pale yellow-fine crystalline "product -.-was washed with'water'and 'dried at C. The crude' product softened at about 210 and melted Wlthdecornposition at 223-'-226C. It-was slightly-holdble or insoluble in all common solvents except chlorobenzene and o-dichlor benzene from which it could be recrystallized. After two recrystallizations the purified product melted at 233-235 C. Analysis of the pure product gave the following:

Calculated for Fmmd CnHzzOzNASfl 51. 57 51. as 3. 24 a. as 8. 87 8. 94 30.64 30. e9 5. es 5. 31

The product is therefore believed to be formed in accordance with the following equation:

The results are not affected by minor Variations in the proportion of formaldehyde. The proportions in the foregoing example correspond to five mols of formaldehyde with three mols of mercaptobenzothiazole although the ratio in which they react is six to three. When the ratio of formaldehyde is increased the identical product is obtained. Thus, increasing the ratio of formaldehyde to seven mols per three of mercaptobenzothiazole the identical product was obtained and in substantially the same yield.

The new products of this invention are useful for accelerating the vulcanization of rubber and for treating tire cord to improve the adhesion of the cord to the rubber and for other uses. This invention is limited solely by the claims attached hereto as part of the present specification.

This application is a continuation-in-part of co-pending application Serial No. 566,950, filed- December 1, 1944.

What is claimed is:

1. The process which comprises heating three molecular proportions of a mercapto thiazole with at least five molecular proportions of formaldehyde and approximately one molecular proportion of ammonia in aqueous medium producing a condensation product of said reactants which contains at least 5 but less than 7 molecular proportions of formaldehyde combined with 3 molecular proportions of said mercapto thiazole, sulfur and nitrogen atoms in the ratio of 3:2 and oxygen, with the elimination of water as a by-product of the condensation.

2. The process which comprises heating three molecular proportions of a mercapto arylene thiazole with at least five molecular proportions of formaldehyde and approximately one molecular proportion of ammonia in aqueous medium producing a condensation product of said reactants which contains at least 5 but less than 7 molecular proportions of formaldehyde combined with 3 molecular proportions of said mer- .4 capto arylene thiazole, sulfur and nitrogen atoms in the ratio of 3:2 and oxygen, with the elimination of water as a by-product of the condensation.

3. The process which comprises heating at about 95 C. three molecular proportions of mercaptobenzothiazole with at least five molecular proportions of formaldehyde and approximately one molecular proportion of ammonia in aqueous medium producing a condensation product of said reactants which contains at least 5 but less than 7 molecular proportions of formaldehyde combined with 3 molecular proportions of mercaptobenzothiazole, sulfur and nitrogen atoms in the ratio of 3:2 and oxygen, with the elimination of water as a lay-product of the condensation.

4. As a new composition of matter the product obtained by heating, with the elimination of Water, 3 molecular proportions of a mercapto thiazole with at least 5 molecular proportions of formaldehyde and approximately 1 molecular proportion of ammonia in an aqueous medium, said reaction product containing at least 5 but not more than 7 molecular proportions of formaldehyde combined with 3 molecular proportions of said mercapto thiazole, sulfur and nitrogen atoms in the ratio of 3:2 and oxygen.

5. As a new composition of matter the product obtained by heating, with the elimination of water, 3 molecular proportions of a mercapto arylene thiazole with at least 5 molecular proportions of formaldehyde and approximately 1 molecular proportion of ammonia in an aqueous medium, said reaction product containing at least 5 but not more than 7 molecular proportions of formaldehyde combined with 3 molecular proportions of said mercapto arylene thiazole, sulfur and nitrogen in the ratio of 3:2 and oxygen.

6. As a new composition of matter the product obtained by heating, with the elimination of water, 3 molecular proportions of mercaptobenzothiazole with at least 5 molecular proportions of formaldehyde and approximately 1 molecular proportion of ammonia in an aqueous medium, said reaction product containing at least 5 but not more than 7 mols of formaldehyde combined with 3 mols of mercaptobenzothiazole, sulfur and nitrogen atoms in the ratio of 3:2 and oxygen.

MARION W. HARMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,779,715 Scott Oct. 28, 1930 2,338,864 Mathes Jan. 11, 1944 Certificate of Correction Patent No. 2,470,555. May 17, 1949.

MARION W. HARMAN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, lines 8 to 17 inclusive, strike out the structure reading:

N-CHzS-C and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 25th day of October, A. D. 1949.

[sun] THOMAS F. MURPHY,

Assistant Oommz'ssioner of Patents. 

